Thyroid & parathyroid
Other thyroid nonneoplastic
Clear cell change
Author: Shahid Islam, M.D., Ph.D.
Last author update: 1 March 2009
Last staff update: 17 September 2020
Copyright: 2002-2023, PathologyOutlines.com, Inc.
PubMed Search: clear cell change thyroid
Table of Contents
Definition / general | Case reports | Gross images | Microscopic (histologic) images | Cytology description | Positive stains | Electron microscopy images | Differential diagnosisCite this page: Clear cell change. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/thyroidclearcell.html. Accessed March 24th, 2023.
Definition / general
- Nonspecific finding in benign and malignant thyroid tumors; also seen in Hashimoto thyroiditis and dyshormonogenetic goiter
- Follicular adenoma and carcinoma: due to empty vacuoles associated with dilated endoplasmic reticulum and Golgi (Ultrastruct Pathol 2001;25:361, Am J Surg Pathol 1988;12:240) or intracellular lipid and mucin (Acta Cytol 2002;46:757)
- Follicular carcinoma with McCune-Albright syndrome: due to uncontrolled fatty acid synthesis (Mod Pathol 1999;12:969)
- Lipid-rich cell adenoma: due to neutral fat
- Medullary carcinoma: may be thyroglobulin negative (Hum Pathol 1985;16:844)
- Papillary carcinoma: due to glycogen
- Signet ring or lipoblast type tumors: vacuoles may contain thyroglobulin (Am J Surg Pathol 1985;9:705)
- Undifferentiated carcinoma: due to glycogen
Case reports
- 29 year old woman with clear cell follicular adenoma arising in ectopic thyroid tissue (Endocr Pathol 1998;9:339)
- 37 year old woman with follicular carcinoma with FNA showing clear cells that were negative for thyroglobulin (Diagn Cytopathol 2000;23:222)
Gross images
AFIP images
Nodular hyperplasia with clear cell change
Microscopic (histologic) images
Contributed by Andrey Bychkov, M.D., Ph.D.
AFIP images
Hashimoto thyroiditis with clear cells
Nodular hyperplasia
Papillary carcinoma:
Clear cell change
Clear cell change
(follicular variant)
Follicular neoplasms:
Follicular carcinoma
Follicular neoplasm with clear cell change
Signet ring follicular adenoma
Oncocytic neoplasms:
Sharp demarcation between clear and oncocytic cells
Gradual transition from oncocytic to clear cells
Both patterns exist in same cell
Renal cell carcinoma metastases:
Clear cell type
Adenoma is thyroglobulin+
Cytology description
- Follicular carcinoma:
- Clearing due to intracellular lipid and mucin
- Cohesive sheets of round / oval cells with abundant pale staining cytoplasm, tumor cells often cluster around branching capillaries, also frequent fat cells with discrete cell borders, cytoplasm distended by fat globules and eccentric nuclei (Acta Cytol 2002;46:757)
Positive stains
- Thyroid tumors are generally thyroglobulin+ (Am J Surg Pathol 1984;8:187), but may be weak / negative
Electron microscopy images
AFIP images
Signet ring follicular adenoma
Marked dilation of cisternae
Differential diagnosis
- Parathyroid carcinoma: metastatic or from parathyroid tissue in thyroid gland
- Renal cell carcinoma
